Last week senator Marco Rubio said on the Sean Hannity show that “Science is settled . . . human life begins at conception.” While some people who support legal abortion might scoff at the senator’s remarks, the fact is that all the evidence stands firmly behind what he said.

Now, science can’t prove a valuable human being, or a person, or someone with an immortal soul begins to exist at conception because concepts like “the soul” “value” or “person” are...